The latest to die of the (A)H1N1 virus were an ayurvedic or traditional medicine practitioner in Pune, 120 kilometres (75 miles) from India´s financial hub Mumbai, and a four-year-old boy in the southern city of Chennai.
Both patients had been unwell for some time, Indian media reported, quoting state health officials.
A man who arrived in western Gujarat state from the United States at the end of July and a woman from Mumbai both died on Saturday, while a school teacher died in Pune on Sunday.
India´s first swine flu death was that of a 14-year-old girl last Monday, also in Pune, where there has been a cluster of cases.
The Indian government, which has urged the public not to panic, is screening travellers arriving at airports and asking people with flu-like symptoms not to go to public places and to seek immediate diagnosis.
Some schools shut amid concern about the virus, as newspapers and television news channels showed queues of people, many in surgical masks, waiting for tests outside medical centres.
As of Sunday, there were 82 new confirmed swine flu cases, taking the total number of people with the virus to 864, the ministry of health said.
Most had either returned to India from abroad or had contact with people who had been overseas.
The government is sending 100,000 doses of the anti-viral drug Tamiflu to affected cities, health minister Ghulam Nabi Azad told the Hindustan Times newspaper.
The World Health Organization said this week that more than 1,150 people have died from swine flu and the virus was now in 168 countries and territories. Nearly 90 percent of deaths have been in the Americas.
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